Blowpipe



April 23, 1940. H. w. JONES ET Al.

BLOWPIPE Filed Aug. so, 1958 2 Sheets-Sheet 1 .dmLl

sm www OOO C mJ. .m WWW, -..m N T Imm A M OB HR m April 23, 1940. H. w.JONES ET AL BLOWPIPE Filed Aug. 50,1958 2 sheets-sheer 2 INVENTRS H HOMRWJONES ATTORNEY ERBERT W. COWIN BY Patented Apr. 23; 1940 PATENT. NOFFICE -l BLOWPIPE Homer W. Jones and Herbert W. Cowin, West- Afield, N.J., assig'nors to Oxweld Acetylene Company, a. corporation of WestVirginia applicati@ august so, 193s, serial No. 227.412 19 claims. (ci.15s-21.4)

This invention relates to blowpipes and more particularly to aself-igniting blowpipe adapted to operate with W pressure fuel gas andprovided with-means for insuring the maintenance of a I small pilotflame after the main iiame has been extinguished.

With the various types of self-igniting blowpipes heretofore used withlow pressure fuel gas, diiiiculty has been experienced in maintaining al l0 pilot flame at the blowpipe nozzle whenthe main supply ofcombustible gas mixture has been interrupted. In blowpipes of this type,the relatively high pressure oxygen passes through a mixer and, by aninjector action, aspirates the relatively low pressure combustible gas(e. g., acetylene) into the mixer. `The acetylene for Vsupporting thepilot flame is usually by-passed around the main acetylene controlvalve. If the oxygen valve is closed suddenly,the injector action isabruptly interrupted and not only is the pilot flame extinguishedbutthere is also danger of a flashback or burning within the blowpipeitself. This is particularly true of the type of blowpipe in'which apair of adjustable valves are used to control the proportions of thecombustible mixture of acetylene and oxygen, and a second vpair of quickshut-off valves are used for turning on and off the supply of acetyleneand oxygen to the blowpipe tips.

80 'Ifo overcome these diiculties, a blowpipe arrangement has beendevised in which means are provided for delaying the closing action ofthe above-mentioned quick shut-olf valves and for insuring that theclosing movement of the valve controlling the supply of oxygen fs notcompleted until after the closing movement of the valve controlling themain supply of acetylene-has been completed. while at the same time asmall pilot ame is maintained on the blowpipe tip. The

same time differential means insures that a reduced flow of oxygen tothe blowpipe nozzle is initiated before the acetylene is turned on. thuspreventing undesirable formation of soot due to too muchfree burningcombustible gas.

It is therefore among the objects of this invention to provide ablowpipe for operation with low pressure fuel gas and including means tomaintain a small pilot flame 'when the main flame is extinguished; toprovide a blowpipe in- '50 cluding means for securing a timedifferential in the operation of the shut-oil' valves controlling thesupplies of combustion supporting gas and' combustible gas,respectively; to provide a blowpipe including means for delaying theclosing action of these shut-off valves; and to provide a blowpipehavinggood flashback resistance, and

which is economical to manufacture, simple in construction, andemcientin operation. These and other objects of the invention will inpart be obvious and in part become apparent from aconsideration of thefollowing description and the accompanying drawings, in which:

Fig. 1 is a side elevational .view of one form of blowpipe embodying theinvention, with parts broken away and other parts in sectionA to il- 10lustrate certain novel features of the invention:

Fig. 2 is a longitudinal sectional view through the blowpipe illustratedin Fig. 1;

Fig. 3 is a transverse section view on the line 3--3 o f Fig. 2; y 15Fig. 4 is a transverse sectional view on the line 4-4 of Fig. 2;

Fig. 5 is a view similar to Fig. 1 of another form of blowpipe embodyingthe principles of the invention; 20

Fig. 6 is a view taken o`n the line 6-6 of Fig. 5 looking in thedirection of the arrows;

Fig. 7 is a transverse sectional view on the line 1-1ofFig.5; Fig. 8 isa transverse sectional view on a some- 25 what larger scale taken on'the line 8--8 of Fig. 5: and

Fig. 9 is a. somewhat enlarged view of a modification of the blowpipeshown in Fig. 5.

For convenience, in the following description, 30 the term acetylenewill be used to denote any suitable combustible gas and the term oxygenwill be used to denote any suitable combustion supporting gas. y Inblowpipes designed for operation with low 35 pressure acetylene (lessthan about 1 lb. per sq. in.) and highpressure oxygen .(about 30-35 lbs.per sq.. in.) the combustible mixture is obtained by passing the oxygenthrough the injector of a.

suitable mixer, whereby the resultant vacuum o thus created causes theacetylene to be drawn into the mixer and thoroughly intermixed with theoxygen. Some blowpipes Vare equipped with pilot light arrangements inwhich a portion of the acetylene is by-passed around the acetylene shut-4,5 ofi' valve so that a small flame may be maintained at the blowpipenozzle when the main supply of combustible mixture is interrupted.

In this type of blowpipe. it is necessary to maintain at. least areduced iiow of oxygen after the main iiow of acetylene has beeninterrupted in order to clear out any combustible mixture presentbetween the mixer and the blowpipe tip.

It is desirable to prevent the supply of combustible mixture frombeingabruptly interrupted .1

and to cause such supply to be reduced gradually to prevent a snappingback of the iiame and to l prevent blowing out of the pilot light by thehigh pressure oxygen present between the shut-oil! valve and theblowpipetip or nozzle. It is desirable also to initiate the oxygen supply iirst,in lighting the blowpipe, to prevent the deposition of soot in themixer, the stem and the tip due to a large volume of free burningacetylene.

For the above reasons, the present invention is directed toth'"provision, in a blowpipe equipped with pilot light means, ofseparate shut-ofi valves for the oxygen and acetylene, which valves arelocated between the usual adjustable throttle valves and the blowpipetip, and to the provision of means for insuring a sequential opening andclosing of these shut-oil' valves and for insuring a gradual reductionin the iiow of the combustible mixture when the shut-ofi.' valves arebeing closed.

Referring particularly to the embodiment of the invention illustrated inFigs. l to 4, inclusive, there is shown a blowpipe comprising a valvebody or block V, a tubular handle H, a front body F, a mixer assembly M,a stem assembly S, and a tip or nozzle N secured to the stem assembly bythe usual clamping nut C. Oxygen enters the valve block V through asuitable nipple D, passes through the usual adjustable throttle valve A,and thence through a quick acting, lever operated, shut-off valve B intothe oxygen tube T, from which it enters the mixer assembly M. Similarly,acetylene passes through inlet nipple D', valves A' and B' and acetylenetube T' to the mixer assembly M where it is mixed with the oxygen. Meansare provided to deliver the combustible mixture from mixer assembly Mthrough stem assembly S to the outlet of nozzle N. Other delivery meansare provided to by-pass a portion of the acetylene through adjustablethrottle or pilot valve P'around shut-oil' valve B' and into tube T' toprovide a pilot flame at the blowpipe nozzle.

The quick acting lever operated shut-oil' valves B and B' are providedwith controlling mechanism including sequential valve actuating means Eand automatically operable retarding means R, to delay the closingmovements oi' the valves, which means and mechanism, in combination withthe other elements of the blowpipe, vform the novel subject matter ofthis invention.

Referring now in more detail to'Figs. 1 to 4, inclusive, oxygen underpressure from the pipple D enters through a passage I in valve body V toa valve chamber II in the throttle valve A. A throttle valve I2,actuated by threaded stem I3 having an external knurled head I4 thereon,seats upon the end of chamber II and admits, restricts or shuts oil! thesupply of oxygen to a second valve chamber I 5; A duct I8 in` the body Vconnects chamber I5 to a central oxygen passage I I forming part of theshut-off valve B.

'I'he valve B comprises a exible diaphragm I8, held in sealingengagement with a shoulder I 9 in a bore in the body V by an inverted,cup shape clamping nut 2 I. The diaphragmI8 seats on the end of passageII to control communication between this passage and an annular passage22. A stem 23 is secured to diaphragm I8 and extends outwardly throughnut 2I, where it is formed for engagement with the novel shut-off valveoperating mechanism comprising the invention and which will be describedmore fully later herein. Spring 24, surrounding stem 23 between theinner end surface of nut 2I and a shoulder 25 on the stem normally urgesthe diaphragm I3 to `a valve closing position.

A duct 25 extends through body V from passage 22 and terminates in acounterbored portion in which is sealed one end of oxygen tube T. Theother end of tube T is sealed in a counterbore in the front body F, anda duct 21 extends from tube Tito a chamber 28 in the body F. Fromthe.chamber 28, the oxygen enters the central passage 29 oi' an injector80 in the mixer assembly M and passes through the passage 29 to the stemassembly S.

Acetylene enters from the nipple D' through a passage 3| to a valvechamber 32 in the valve A' (which is identical to the valve A). A duct34 in body V connects a second valve chamber 33, to the central passage35 of the valve B', which is identical to valve B except that the inletacetylene passage is larger in cross-sectional area than the inletoxygen passage I1 in valve B. From the annular passage 36 of valve B',the acetylene may pass through a duct 31, acetylene tube T and duct 33in front body F to a chamber 39 in body F. The rear end of the injector30 is tightly engaged and countersunk in chamber 28 to form a sealbetween chambers 28 and 39. Oxygen leaving the forward end oi injector39, aspiratesacetylene from chamber 39 through annular ducts-40 in theinjector and through annular passages 4I between the forward end of theinjector and the mixer casing 42 into the stem assembly S. A combustiblemixture is thereby delivered through the outlet ofthe nozzle or tip N.

Acetylene for the pilot ilame passes from valve chamber 32 through aduct 43 to inlt chamber 44 in pilot valve P. An oriflced diaphragmmember 45, seated against the end of chamber 44, separatesthis chamberfrom an outlet chamber 46. Communication betweenl the inlet and outletchambers of valve P is controlled by a slidable stem 41, associated withthe orifice in member 45 and secured to a flexible diaphragm 4l which,in turn, is held against a shoulder 49 by a hollow nut 50. A threadedadjusting s'crew 5I, on which is secured a friction plug 52, engages theouter end of stem 41 and is formed with a ker! 53 for engagement by ascrew driver, or other suitable means, for adjusting the opening of thepilot valve. Spring 54, seated on member 45 and engaging a shoulder onstem 41 acts to retract the stem from the orifice when screw 5I isloosened. From the outlet chamber 46, a duct leads to the annular outletpassage 38 of acetylene shutoff valve B', thus permitting acetylene toby-pass this valve and supply a small quantity oi' acetylene to the tubeT' at all times when the acetylene adjustable throttle valve A' isoperi.

`As explained at the beginning of this description, an important featureof the present invention is the novel mechanism for opening and clos ingthe shut-off valves B and B in a preselected sequence and for delayingthe closing movement of both valves to prevent the deposition of sootdu'e to free burning acetylene in the various blowpipe passages and themixer M and tip or nozzle N, and to prevent extinguishing the pilotflame at the outlet of the nozzle N, One embodiment of such mechanismwill now be described.

As best shown in Fig. 1, a bracket 56 is secured to the handle Hadjacent a slot 51' in the latter.

Mounted on a pivot 58 on the bracket 55 is an operating member such as alever 59 comprising an operating arm 60 extending rearwardly fromthepivot 5l along the exterior of the handle H and a bell crank arm 6|disposed within the handle. The inner end 62 of the bell ,crank arm 6|is forked and pivotally connected to the piston 63 of adashpot mechanism64, the' cylinder 65 of which is pivotally connected to a rib 66 on therear end of the front body F.

. The base of the cylinder is bored radially to form a valve chamber 61,communicating with the atmosphere through a small port 68 and with theinterior of the cylinder through a small port 69. An adjustable meanssuch as a metering plug 10, threaded in chamber 61, controls the rate atwhich fluid escapes from the dashpot, and a filter 1|, of felt or othersuitable material, is engaged by the plug adjacent the port 68.

The piston 63 is formed with a recess 12 in which is seated a spring 13.At its forward end,

spring 13 engages a spring guidev 14, comprising a` recessed base 15apertured as at 16 and engaging the end wall of the cylinder 65, and'arearwardly extending stem 11. The forward end of piston 63 is reduced toreceive suitable packing 18 engaging the internal surface o'f cylinder65 and held in placeby a packing nut 19.

As best shown in Figs. 4 and 1 the stem 23 of each quick shut-off valveB, B' is formed with a reduced threaded sectionon which is secured anadjustable bearing cap such as a flanged nut 8|. Two similar levers 82are pivotally mounted at 83 on the forward portion of the valve body V.Each lever has a rearwardly extending angular arm 84 slotted to engageone of the stems 23 beneath the nut 8|. The forward arm 85 of each leveris curved to form a cam surface engaging a roller 86 rotatably mountedat the elbow of the bell crank arm 6| of the lever 59. The cam surface81 of the oxygen lever is formed with a sharper degree of curvature thanthe cam surface 88 of the acetylene lever, whereby the roller 86 willrock the oxygen lever before it rocks the acetylene lever, when theoperating lever 59 is depressed to open the valves B, B'.

In operation, lever 59 is depressed to open valves B, B', compressingspring 13 of dashpot 64. Valves A, A' are then manipulated to obtain thedesired flame adjustment and pilot valve P is adjusted to provide asufllcient ow of acetylene to maintain a pilot ame at the nozzle N. Whenlever 59 is depressed, the opening movement of the oxygen valve B isinitiated before that of the acetylene valve B', due to the dierence inthe cam surfaces 81 and 88, thus initiatingthe flow o f oxygen beforethe ow of acetylene and preventing the deposition of soot in theblowpipe, as previously explained.

When lever 59 is released, dashpot 64 delays the return movement of thelever to itsv normaly or initial position. In turn, roller 86 on lever59 delays the release of levers 82. Thus, oxygen continues to entermixer M to aspirate acetylene and the size of the main flame graduallydiminishes, permitting any gas mixture in the blowpipe to pass throughnozzle N and be consumed. When the valves B, B' are finally fullyclosed, a small quantity of acetylene continues to ow through pilotvalve P so that a small flame is maintained at the end of nozzle N. Itwill be noted that the controlling mechanism initiates the interruptionin the flow of one gas before initiating the interruption in the flow ofthe other gas.

By the delaying action of the dashpot, and thev differential closingaction of the cam surfaces 81, 68, flashback in the blowpipe isprevented and the flow of oxygen is reduced gradually so that a. thepilot flame will not be blown out. It should be noted thatthe functionof preventing the blowing out of the pilot flame is performed bytheretarding mechanism R. Therefore, the sequence of operation. of valvesB, B' -may bealtered, or the valves may be designed to operatesimultaneously, without affecting the action of mechanism R inmaintaining the pilot ame.

Except for changes in the disposition of valves A, A' and B, B', and inthe construction of valves B, B', the modified arrangement shown inFigs. 5 to 9, inclusive, is similar to that heretofore described, 'andlike reference characters are used to denote like, or corresponding.parts.

In the modified construction, the main throttle valves A and A' althoughidentical in internal construction and operation with those heretoforedescribed are separate from the body V, and are secured in counterbores89, 90 in the rear of body V. The valves B, B' are mounted in theforward portion of body V (see particularly Figs. 6' and 8). The centralinlet passages |1, 35 and the annular outlet passages 22, 36 are drilledin the body V. Each valve member comprises a sleeve diaphragm 9|,moulded around the inner end of the stem 23, and clamped between asleeve 92, sealed to a shoulder 93 in the annular outlet passage 22 or36 by suitable means such as solder 94, and a hollow clamping nut 95threaded on the outer end of the sleeve. A spring 24, surrounding eachstem 23 and engaging a suitable shoulder 96 on the stem at one end andan inner sleeve 91 surrounding the stem and engaging thelnut 95 at theother end, normally urges each valve to a closed position.

In this construction, oxygen enters through the valve A,. and passesthrough duct I6, inlet passage l1, outlet passage 22, and oxygen tube T(which communicates with the 'outlet passage) to the mixer assembly M.Similarly, acetylene passes through valve A', duct 34, passages 35 and36, and acetylene tube T to the mixer assembly. The gas for the pilotflame enters pilot valve P from duct 34 through duct 43 and passestherefrom through another duct (not shown) to the outlet chamber 36.

A bracket 98, formed on the inner end of valve body V, pivotallysupports the operating levers 99 fon the valves B. B'. The forward ends|00 of the levers have identical cam surfaces engaging the roller 86 onlever 59. The rear end |0|, |02, of each lever extends inwardly and issuitably slotted to engage the rounded under surface of the head |03 ofan adjusting bolt |04 threaded in a recess in the outer end of each stem23. The rear end |0| of the oxygen lever makes a smaller angle with theforward end than does the-rear end |02 of the acetylene lever (see Figs.5 and 6). Accordingly, when lever 59 is depressed, the oxygen valve Bwill be opened before 'the acetylene valve B', and, when lever 59 isreleased. oxygen valve B will close last.

In this modification. as in the form of blowpipe shown in Figs. l to 4,the dashpot mechanism delays the closing action of the vshut-off valvesand thereby prevents blowing out of the pilot flame. Similarly, the timedifferential in the operation of the valves B, B' may be varied orreversed without affecting the operation of the retarding mechanism R.This permits wide latitude in the adjustment of the blowpipe for variousspecial conditions without disturbance of the mechanism for maintaininga pilot flame on nozzle or tip N.

Fig. 9 illustrates another manner in which the time differentialoperation of the valves B, B' may be attained, and which permits readyadiustment of the sequence of operation. As shown in this |00, andadjustment for the sequential opening of the valves is attained throughrelative adjustment of the bolts |04 in the stems 23.

- As the modifications shown in Figs, 5 vto 9, inclusive, operate in thesame manner as that shown in Figs. 1 to 4, inclusive, furtherdescription of such operations seems unnecessary.

It should be noted that the rate of oper ation of the dashpot 6l, ascontrolled through adjustment of metering plug 'l0 with respect to post68, is critical, as the time delay in the closing of valves B, B must beaccurately adjustable to insure maintenance of .the proper size pilotflame without anyundue waste of gas.

While the valves B, B' have been shown as associated'with the valve bodyV in both-instances, it will be obvious that these valves could beassociated equally well .with the front body F.

From the foregoing description, it will be apparent that. the blowpipeof' this invention includes a:novel combination of elementsenhancing theflashback resistance of theblowpipe and insuring the' maintenance of apilot flame on the blowpipe tip or nozzle. This combination includes thequick shut oi valves B, B', the sequential operating means E and theretarding'mechanism R; By varying the relativecurvature of the forwardends of the levers 82) in the modification shown in Figs. 1 to 4, or ofthe rear ends of the 1evers'99 in that shown in Figs'. 5 to 8; or byfadjustment of the bolts |04 in the form shown in Fig. 9, either theflow of oxygen or the '-ow of acetylene may be initiated first andterminated last, or both may be turned on and off simultaneously. In anyinstance, both shut off valves are. controlled by the single operatinglever 59 and the retardingmechanism will .functionequally well to insuremaintenance of the pilot ame on the tip or nozzle N.

While certain embodiments of the invention .have been illustrated anddescribed in detail, it will be obvious that the invention may beotherwise embodied and the dimensions and interrelation of parts changedso long as the 1objects of the invention are attained.

I0= We claim:

2. A blowpipe as claimed in claim 1, in Awhich said mechanismincludesadjustable means controlling the rate of operation of saidretarding means.

3. A blowpipe comprising, in combination, a

nozzle; a tubular handle carrying said nozzle;

means for delivering a combustible mixture of fuel gas andcombustion-supporting gas through the outlet Aof said nozzle to producea ame; and mechanism for controlling the ilow of both the fuel gas andthe combustion-supporting gas which form saidv mixture, such mechanismcomprising means operable to shut off such mixture-forming gases, andmeans within said handle and operable automatically to retard the actionof such shutting-off means.

4. A blowpipe comprising, in combination, a nozzle; means for deliveringa combustible mixture of fuel gas and combustion-supporting gas throughthe outlet ofsaid nozzle to produces. main flame and for delivering fuelgas thro'ugh said. outlet to` provide a pilot flame while the deliveryofsuch combustible mixture is interrupted, said pilot flame being adaptedto reignite such mixture when the delivery of the latter isre-established; and mechanism for controlling the flow of both thecombustion-supporting gas and the fuel gas which form said mixture, suchmechanism comprising means operable to shut off such mixture-forminggases, and means operable automatically to delay the action of suchshutting-oil means, to avoid extinguishing said pilot ame.

5. A blowpipe as claimed in claim 4, inA which such shutting-off meansis constructed and arranged to initiate the interruption of the flow ofone of such mixture-forming gases before initiating the interruption ofthe flow of the other mixture-forming gas.

6. A blowpipe as claimed in claim 4, in which said mechanism includesadjustable means for controlling the rate of operation of said delayingmeans.

7. A blowpipe comprising, in combination, a valve block; a tubularhandle; a nozzle having an outlet; means for delivering acombustiblemixture of fuel gas and combustion-supporting gas throughsaid outlet to produce a flame; and mechanism for controlling thedelivery of both th'e fuel -gas and the'combustion-supporting gas whichform such mixture, such mechanism comprising throttle valves, a shut-offvalve interposed between each of said throttle valves and said nozzle,means for actuating said shut-off valves. and means operableautomatically to retard the closing of said ,shut-off valves after thelatter have been operatedvby said actuating means.

8. In the blowpipe claimed in claim 7, means for maintaining a pilotflame adjacent the nozzle outlet when vsaid shut-oiyalves are closed.

9. The blowpipe claimed in claim 7 in which all of. said valves aremounted on said valve block.

10. The blowpipe claimed in claim 7 in which said shut-oil? valves aremounted on said'valve block and 'within said tubular handle.

11.l Intheblowpipe claimed in claim 7, means, including an adjustablethrottle valve mounted on said valve block and interposed between thethrottle valve and the shut-off valve controlling the fuel gas, formaintaining a pilot name adjacent the nozzle outlet when the shut-olfvalve controlling the fuel gas is closed.

12. In a blowpipe, in combination, a valve block having oxygen and fuelgas passages therein; a nozzle; oxygen and fuel gas tubes communicatingwith said nozzle; throttle valves controlling the admission of oxygenand fuel gas to said passages; shut-off valves interposed between saidtubes and said passages; mechanism for operating said shut-oi valvesautomatically in a preselected sequence; and means for delaying theclosing of said shut-oil valves.

13| A blowpipe as claimed in claim l2, in which said valve block isformed with a duct intersecting said fuel gas passage between thethrottle valve and the shut-ol! valve and communicating with the fuelgas tube between the shut-oil valve and the nozzle to maintain a pilotflame adjacent said nozzle when the fuel gas shut-off valve is closed.

14. In a blowpipe, in combination, a valve block having oxygen and fuelgas passages therein; a

pair of throttle valves respectively controlling the admission of oxygenand fuel gas to said oxygen l and said fuel gas passages, respectively;a front body; a tubular handle connecting said front body to said valveblock; a nozzle secured to said front body; tubes in said handle forrespectively conducting oxygen and acetylene from said passages to saidfront body; oxygen and acetylene shut-off valves adapted respectively topermit or prevent the flow of oxygen and acetylene from said passage.;to said tubes; a pair of levers pivotally connected to said valve blockand each operatively associated with one of said valves, said leverseach being formed with a cam surface; an operating member pivotallyconnected to said handle; and means on said operating member engagingsaid cam surfaces to initiate the operation of said rst-named levers andsaid shut-oil valves in a preselected sequence.

15. In the blowpipe claimed in clai'm 14, means for maintaining a pilot4ame adjacent said nozzle when said shut-off valves are closed; and adashpot mechanism operatively connected to said front body and saidoperating member for delaying the operation of said shut-off valves.

16. In the blowpipe claimed in claim 14, means for maintaining a pilotflame adjacent said nozzle when said shut-off valves are closed; adashpot mechanism operatively connected to said front body and saidoperating member for delaying the operation of said shut-off valves; anda metering plug operatively associated with said dashpot mechanism.

17. The blowpipe claimed in claim 14, in which said shut-oil valves areeach provided with an adjustable bearing cap engaging one of saidlevers.

18. The blowpipe claimed in claim 14, in which said cam surfaces areidentical and said levers are each provided with an end portion bent atdifferent angles to the main body of the lever

